SG Heritage Dictionary

Flatten [Verb intransitive] Webster's Dictionary 1828

1. flat'n.

2. To grow or become even on the surface.

3. To become dead, stale, vapid or tasteless.

4. To become dull or spiritless.

Flatten [Verb transitive] Webster's Dictionary 1828

1. flat'n.

2. To make flat; to reduce to an equal or even surface; to level.

3. To beat down to the ground; to lay flat.

4. To make vapid or insipid; to render stale.

5. To depress; to deject, as the spirits; to dispirit.

6. In music, to reduce, as sound; to render less acute or sharp.

Flatten [Adjective] Webster's Dictionary 1913

1. To reduce to an even surface or one approaching evenness; to make flat; to level; to make plane.

2. To throw down; to bring to the ground; to prostrate; hence, to depress; to deject; to dispirit.

3. To make vapid or insipid; to render stale.

4. To lower the pitch of; to cause to sound less sharp; to let fall from the pitch.

Flatten [Verb intransitive] Webster's Dictionary 1913

To become or grow flat, even, depressed dull, vapid, spiritless, or depressed below pitch.

Flattened [Imperfect tense and past participle] Webster's Dictionary 1913

Flattening [Participle present tense] Webster's Dictionary 1828

Making flat.

Flattening [Present participle and verbal noun] Webster's Dictionary 1913